Anthropogenic Specimen (Man Made)

Citrine Quartz

Citrine (Silicon Dioxide, SiO2)

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Blue cabochon gemstone, likely synthetic glass or dyed stone

Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Sea Glass

Silicon dioxide (mostly)

Polished black stone, likely black obsidian

Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)

Tumbled milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite or Goethite inclusions

Sandstone (with man-made markings)

Arenite (composed primarily of Quartz, SiO2)

Milky quartz (likely rough quartz crystal)

Quartz, silicon dioxide (SiO₂)

Crescent Pebble

Weathered Quartzite or Sandstone Fragment

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Weathered iron-rich concretion or ironstone nodule

Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)

Vesicular basalt (probable iron-rich volcanic rock)

Basalt; chiefly plagioclase, clinopyroxene, olivine, and Fe-Ti oxides

Asphalt (Bituminous Concrete)

Bituminous mix / Anthropogenic conglomerate

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Chert (Arrowhead Shard)

Microcrystalline silica (SiO2)

Tumbled quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Cherry Quartz with Rose Quartz

Crystalline Quartz (SiO2) with glass-based synthetic components

Rainbow Hematite (Titanium Coated)

Iron(III) oxide (Fe2O3) with Titanium/Metal Oxide coating

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Fordite

Anthropogenic paint-rock

Blue Obsidian

Volcanic Glass (SiO2 with inclusions)

Decorative mosaic cross containing mixed rock and glass fragments

Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass

Slag

Anthropogenic Vitrification Product / Silicate Slag

Green glass-like mineral specimen, likely fluorite

Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass

Goldstone

Aventurine Glass (Man-made glass with copper inclusions)

Sandstone (likely Fossilized Wood or Concrete Simulacrum)

Arenite / Silicified Wood / Anthropogenic Concrete

Polished milky quartz (likely quartz worry stone or wand)

Quartz, silicon dioxide (SiO₂)

Clear quartz sphere

Quartz (silicon dioxide, SiO₂)

Chert Arrowhead (Lithic Tool)

Microcrystalline quartz (SiO2) - Archeological lithic artifact

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Bismuth

Bismuth (Bi)

Man-made Carved Stone (Scream Mask/Skull motif)

Carved Soapstone or Serpentine-rich rock

Blue Obsidian (Cullet Glass)

Silicon Dioxide (Amorphous Glass)

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Opalite

Synthetic Opalite Glass / Opalized Glass